FUNCTIONAL CONSEQUENCES OF DISULFIDE BOND FORMATION IN GELSOLIN

Gelsolin is an actin monomer binding and filament severing protein syn thesized in plasma and cytoplasmic forms differing by an N-terminal am ino acid extension and a disulfide bond between Cys-188 and Cys-201. T o determine whether this bond altered gelsolin regulation or function, oxidized and reduced plasma gelsolins were assayed for severing, mono mer binding and nucleation activity at a variety of rate-limiting calc ium concentrations. The results indicate that the disulfide bond in do main 2 of gelsolin influences the transmission of information from C-t erminal regulatory sites to functional sites in the N-terminus.